Hirotaka Shibuya

Synthesis of two pairs of enantiomeric C18-sphingosines

Abstract Two pairs of enantiomeric (D- erythro , L- erythro , D- threo , L- threo ) C 18 -sphingosines have been synthesized from Z -butene-1,4-diol utilizing Sharpless asymmetric epoxidation and a regiospecific ring-opening reaction of the resulting C 4 -chiral epoxide with an azide anion.

Marine natural products. XXV. Biologically active tridecapeptide lactones from the Okinawan marine sponge Theonella swinhoei (Theonellidae). Structure of theonellapeptolide Id

Abstract Theonellapeptolide Id ( 1 ), a tridecapeptide lactone, was isolated from the Okinawan marine sponge Theonella swinhoei and the structure 1 was determined. A new HPLC analysis method for analyzing the amino acid composition of 1 containing N-methyl amino acids was devised.

Successive methyl migrations occurring in the acid treatment of 1-epoxyethyl-1,2,2-trimethyl-cyclopentane derivative

Abstract Acid treatment of (IR, 3S,1′S)-1-(1′,2′-Epoxyethyl)-1,2,2-trimethyl-3-acetoxymethyl-cyclopentane 6 ) has been shown to yield three products ( 8 , 9 , 10 ), among which 8 and 9 are 1-oxa-bicyclo[3.3.0]octane derivatives formed via successive methyl migrations followed by an oxorane ring closure.