A process for the asymmetric preparation of a compound of the formula ##STR1## wherein the hydrogen at 3a and 7a are of cis or trans configuration and their non-toxic, pharmaceutically acceptable acid addition salts comprising submitting a compound of the formula ##STR2## to a Hoffman reaction and reacting the resulting product with formaldehyde in the presence of cyanide ions and acid halide of benzoic acid or an aliphatic carboxylic acid of 1 to 5 carbon atoms to obtain a compound of the formula ##STR3## wherein R is acyl of benzoic acid or aliphatic carboxylic acid of 1 to 5 carbon atoms, cyclizing the latter to form a compound of the formula ##STR4## selectively hydrolyzing the latter with a dilute aqueous mineral acid to obtain a compound of the formula ##STR5## subjecting the latter to hydrolysis with a concentrated aqueous mineral acid to form the acid addition salt of a compound of claim 1 and optionally forming the free base.
一种不对称制备式为##STR1##的化合物及其非毒性、药学上可接受的酸盐的方法,其中3a和7a处的氢是顺式或反式构型,包括将式为##STR2##的化合物提交给Hoffman反应,并在
氰离子和
苯甲酸或1至5个碳原子的脂肪族
羧酸的酸卤存在下,与
甲醛反应,以获得式为##STR3##的化合物,其中R为苯甲酰基或1至5个碳原子的脂肪族
羧酸酰基,将后者环化形成式为##STR4##的化合物,选择性地用稀溶矿酸
水水解后得到式为##STR5##的化合物,将后者用浓矿酸
水水解后形成第1项化合物的酸盐,并可选择性地制备游离碱。