Masakatsu Shibasaki

Synthesis of 9(0)-Methano-Δ6(9α)-PGI1: The highly potent carbon analog of prostacyclin

Abstract A new Prostacyclin analog, 9(0)-Methano-Δ 6(9α) -PGI I , was synthesized by utilizing intramolecular pinacolic coupling reaction as the key step and was shown to be more potent than carbacyclin in inhibition of platelet aggregation.

A new method for the conversion of aldehydes (RCH2CHO)to acetylenes (RC&.tbnd;CH) via 1-alkenylstannanes. Application to the synthesis of 9(O)-thia-Δ6-PGI1

Abstract A method for the conversion of aldehydes to acetylenes via 1-alkenylstannanes is reported, including its application to the synthesis of 9(O)-thia-Δ 6 -PGI 1 .

A total synthesis of d1-coriolin

Abstract A total synthesis of d1-coriolin has been accomplished starting from 1,3-cyclooctadiene, in which a rational and efficient introduction of various functional groups to the synthetic intermediate, 7-endo-t-butyldimethylsilyloxybicyclo[3.3.0]-oct-8-en-2-one, is involved.

The total synthesis of dl-coriolin

Abstract The total synthesis of dl -coriolin has been accomplished via the key intermediate (5RS, 7SR) - 7 - t -butyldimethylsilyloxybicyclo[3.3.0]oct - 8 starting from 1,3 - cyclooctadiene.

Regiocontrolled conversion of α,β-unsaturated ketones to olefins via allylsilanes: synthesis of d1-9(0)-methano-Δ6(9α)-PGI1

Abstract A synthesis of d1 -9(0)-methano-Δ 6(9α) -PGI 1 ( 1 ), a more potent prostacyclin analog than carbacyclin, has been accomplished utilizing regiocontrolled transformation of the enone to the olefin via the allylsilane as a key step.

A new alkyltin (IV)-mediated coupling reaction of aldehydes to olefins

Abstract Various olefins were synthesized by coupling reactions via the corresponding α-stannylalkyl halides derived from aldehydes. A cross-coupling reaction using the different types of α-stannylalkyl halides, based on the difference of their reactivities, was also achieved.

Regioselective transformation of internal alkynes to unsymmetrical ketones. Novel routes to key intermediates for the synthesis of carbapenem and carbacephem skeletons

Abstract Hydrostannation of the internal alkynes ( 2 , 7 ) with tri-n-butyltin hydride afforded the alkenylstannanes ( 3 , 8 ) regioselectively, from which the ketones ( 6 , 11 , 12 ), intermediates for the synthesis of carbapenem and carbacephem skeletons, were synthesized.

The efficient synthesis of chiral key intermediates for monobactam antibiotics

Abstract Chemical asymmetric syntheses of the key intermediates (4,6,8) for the synthesis of monobactam antibiotics (SQ 26776 (azthreonam), sulfazecin, and SQ 26180) are accomplished from (±)-4-phenylsulfonyl-2-azetidinone.

Total synthesis of the carbon analog of Δ6-PGI1

Abstract The first total synthesis of the carbon analog of 6,9α-oxide-11α,15α-dihydroprosta-6(7),13E-dienoic acid ( Δ 6 -PGI 1 ) is described starting from 1,3-cyclooctadiene.

A simple, highly stereocontrolled total synthesis of (+)-hirsutic acid

Abstract A chirally directed total synthesis of (+)-hirsutic acid from 1,3-cyclooctadiene has been accomplished in a highly stereocontrolled manner.