| 摘要 |
<p>Cmpds. of the general formula:- (I) where OR is hydroxy, opt. esterified or etherified X is C=O or wavy lines represent alpha or beta configuration. Intermediates suitably protected at 3 for modification of group X. A mixture of (II) (25 pts.), methanol (84 pts.) and triethylamine (0.5 pts.) is heated until homogeneous when acetone cyanhydrin (23.3 pts.) is added. Upon addn. of approx. 10 pts. water the reaction mixture changes to a solid mass. After cooling to 0-5 deg. and filtration gives the crude product which is washed with methanol and air dried. Recryst. from ethyl acetate or methanol gives III mp 215-218 deg.</p> |
