PRODUCTION OF TETRAHYDROFURYL CARBAMATE DERIVATIVE

PROBLEM TO BE SOLVED: To simply obtain the above compound having HIV protease inhibitory activity useful as a preventive medicine or therapeutic agent or their intermediate for acquired immune deficiency syndrome by using a partially new starting compounds, etc. SOLUTION: This tetrahydrofurylcarbamate derivative of formula III [the comformation of (R) marked C is R conformation] is obtained by carrying out of reaction of an epoxy derivative of formula I [the conformation of (S) marked C is S conformation] with a N-isobutyl-benzenesulfone amide, a partially new compound, of formula II (A is a nitro, an amino and an amino group having a protective group). The compounds which has NH2 as A in compounds of formula III is useful as a preventive medicine or therapeutic agent for acquired immune deficiency syndrome. The epoxy derivative of formula I is obtained, for example, by carrying out the cyclization reaction of a sulfonic acid ester derivative of formula IV (B is methyl, phenyl, methoxyphenyl, etc.) in an alkyline condition.