摘要:
A process is described for obtaining a single enantiomer from a racemic mixture of the bicyclic lactam 2-azabicyclo�2.2. 1! hept-5-en-one by seeding a supersaturated solution of the lactam and a solvent with a single enantiomer of the lactam.
摘要:
Enantiomeric glutarimides such as aminoglutethimide and rogletimide are prepared by cyclisation of a corresponding ester-nitrile which is a good substrate for biotransformation with an enantiospecific esterase.
摘要:
A process for the preparation of lipolic acid (thioctic acid), or a derivative thereof, is one in which a 2-substituted cyclohexanone is transformed in an oxidation reaction to a lactone having formula (I), wherein X is a heteroatom substituent.
摘要:
A cycloalkanol is prepared by cycloaddition between a diene and a vinyl ester, wherein the ester is derived from a carboxylic acid of sufficient molecular weight to enable the reaction to be carried out at atmospheric pressure while above 150.degree. C., and the corresponding reaction between the diene and vinyl acetate generates a pressure above 4 atmospheres.
摘要:
Azlactone (3), or the opposite enantiomer thereof, undergoes biotransformation, using suitable enzymatic activity, in the presence of a compound YH to form a N-acyl-amino acid (2), wherein R1, R2 and R3 are each not hydrogen and are independently selected from groups containing up to 20 carbon atoms, optionally with any combination of R1, R2 and R3 being joined together to form at least one ring, X is selected from groups containing up to 20 carbon atoms, and Y is selected from the group consisting of —OH, -Oalkyl and -Nalkyl. Amino acid (1), or the opposite enantiomer thereof, can be prepared in high enantiomeric excess from N-acyl amino acid (2), by converting Y to OH.
摘要:
A process for the preparation of optically-enriched pipecolic acid as a salt with an optically-active acid, comprises asymmetric transformation of pipecolic acid, as a racemic mixture of a mixture enriched in the opposite enantiomer from that desired, with the optically-active acid in a solvent comprising an acid that causes racemisation, in the absence of aldehyde.
摘要:
A process for the racemization of an enantiomerically-enriched compound of formula (3), comprises treatment of enantiomerically-enriched (3) with a base to obtain anion (4), optionally in protonated form, which is then combined with CH.sub.2 =CH--Y.sup.1 to form racemic (3), ##STR1## wherein Ar=aryl or heteroaryl; Ak=C.sub.1-20 alkyl; X=CN, CO.sub.2 R, CONR.sup.1 R.sup.2, and COR; Y and Y.sup.1 are independently selected from CN, CO.sub.2 R, CONR.sup.1 R.sup.2 and R, R.sub.1 and R.sub.2 are independently selected from H and C.sub.1-20 alkyl; optionally as a salt thereof. This racemization process can be used as part of an efficient synthesis of enantiomerically-enriched verapamil or aminoglutethimide.
摘要翻译:一种对映异构体富集的式(3)化合物外消旋化的方法包括用碱处理对映异构体富集的(3),以获得任选以质子化形式的阴离子(4),然后将其与CH 2 = CH- Y1形成外消旋(3),X(Ar)(Ak)C(CH2)2Y(3)其中Ar =芳基或杂芳基; Ak = C 1-20烷基; X = CN,CO2R,CONR1R2和COR; Y和Y 1独立地选自CN,CO 2 R,CONR 1 R 2和R 3,R 1和R 2独立地选自H和C 1-20烷基; 任选地作为其盐。 该外消旋化方法可用作有效合成对映体富集的维拉帕米或氨基己二酰亚胺的一部分。
摘要:
Iodotamoxifen derivatives which are compounds of formula (3) ##STR1## wherein X represents 3- or 4- iodo and R.sup.1 and R.sup.2, which may be the same or different, represent C.sub.1-3 alkyl, especially methyl or ethyl, groups or R.sup.1 represents a hydrogen atom and R.sup.2 a C.sub.1-3 alkyl group or R.sup.1 and R.sup.2 together with the nitrogen atom to which they are attached represent a saturated heterocyclic group, especially a pyrrolidino, piperidino, 4-methylpiperidino or morpholino group, and their pharmaceutically acceptable acid addition salts are potent anti-estrogenic compounds useful for treatment of estrogen receptor-positive (hormone-dependent) breast cancers.Radioisotopic iodotamoxifen derivatives of formula (3) are useful in radiotherapy or gamma ray imaging of these cancers.
摘要:
The subject invention pertains to a process for preparing a compound having a formula (4) or (5), in either optically-enriched or racemic form, wherein R1, R2, R3 and R4 are independently selected from hydrogen, alkyl, aryl, alkaryl, aralkyl and acyl groups. In one embodiment, the process of the invention comprises mixing with a plant extract obtained from crushed daffodil bulbs or crushed snowdrop bulbs an oxidative cyclisation precursor of the compound.
摘要:
The subject invention concerns a process for preparing a compound of formula (3) ##STR1## in enantio-enriched form, comprising reducing a compound of formula (4) ##STR2## using an asymmetric enantiospecific reductant, wherein A.sup.1 .dbd.A.sup.2 .dbd.H or A.sup.1, A.sup.2 .dbd.O; B.sup.1 .dbd.B.sup.2 .dbd.H or B.sup.1, B.sup.2 .dbd.O; Z.dbd.H, C.sub.1-20 alkyl or a precursor thereof, or a removable protecting group for nitrogen, e.g, acyl or alkyloxycarbonyl; Y.dbd.H or a substituent; R.sup.1 .dbd.C.sub.1-20 alkyl; and R is an optional, additional substituent.