1,4-ADDITION REACTION OF NON-ALLYLIC SULFONYL CARBANION WITH CYCLOPENTENONE DERIVATIVE IN THE PRESENCE OF HMPA. SYNTHESIS OF 15-KETO PROSTAGLANDIN F<sub>1</sub>
1,4-Addition reaction of aliphatic (non-allylic) sulfonyl carbanion to cyclopentenone derivative was studied to build the vinyl ketone function at the β position of the carbonyl of cyclopentenone. 15-Keto PG F1 (6) was synthesized fromsulfone ketal 1 and cyclopentenone derivative 2.
A hydroxy-1-alkyne is reacted with a tin hydride compound, and the obtained (E,Z)-hydroxyvinylstannanes are separated to give the (E)-substance which is further converted to a vinylcopper complex shown by
followed by the conjugate addition reaction with an &agr;, &bgr;-unsaturated cyclopentenone, and the deprotecting reaction is subsequently carried out to prepare a prostaglandin or an intermediate of prostaglandins easily, efficiently and industrially favorably.
This invention relates to the novel processes for the preparation of a 16-methoxy-16-methyl prostaglandin E.sub.1 derivative and to the novel intermediates useful therefor.
Regioselective Reaction of Allylic Carbanion Derived from 1-Phenylthio-2-octene with Conjugated Cyclopentenone Derivative and Synthesis of Prostaglandin E<sub>1</sub>
The reaction of the allylic carbanion derived from 1-phenylthio-2-octene with conjugated cyclopentenone derivatives in the presence of hexamethylphosphoric triamide (HMPA) regioselectively gave the 1,4 adduct at the α carbon of the allylic sulfide. The reaction was employed for the synthesis of prostaglandin E1.