Prepn. of methoximino aldehyde intermediate for prosta glandin(s) - by oxidising 1-hydroxy-2-(6-carboxy-hex-2-en-1-yl)-3,4-protected hydroxy-cyclopentane deriv, converting to methoxime, hydrolysing, converting to bis-tri:methyl silyl cpd. and oxidising

摘要

The prepn. of methoximino aldehyde derivs. of formula (I) comprises (a) oxidising a hydroxy cpd. of formula (II) to the oxo cpd. of formula (III); (b) converting (III) to the methoxine of formula (IV); (c) hydrolysing the hydroxyl protecting gp. in (IV) to give the diol of formula (V); (d) converting (V) into the bistrimethylsilyl ether of formula (VI) and (e) oxidising (VI) to give (I). In formulae, R1 = MeO or N-methane sulphonylamido; R2 = tetrahydropyranoyl or alpha-ethoxyethyl. USE/ADVANTAGE - (I) are intermediates in the synthesis of E2 series prostaglandins used to induce labour and to prepare for instrumental cleaning of the uterus in intact pregnancies, missed abortions or hydratidiform mole (i.e. in D and C operations). The use of (I) as the intermediate in prostaglandin synthesis enables fewer reaction steps to be used than previously and the whole process is more environmentally friendly.