- Regiochemical control of the ring opening of 1,2-epoxides by means of chelating processes. 8. Synthesis and ring opening reactions of cis- and trans-oxides derived from 3-benzyloxycyclohexene and 2-benzyloxy-5,6-dihydro-2H-pyran
-
The regiochemical outcome of the ring opening of 1,2-epoxides bearing polar remote functionalization through chelation processes assisted by metal ions, was verified in cyclic oxirane systems having the polar functionality in an allylic position to the oxirane ring. The diastereoisomeric cis/trans epoxide pairs 5,6 and 7,8 derived from 3-benzyloxycyclohexene, and 2-benzyloxy-5,6-dihydro-2H-pyran, respectively, were prepared and several of their opening reactions were studied. The regioselectivity observed largely depends on the reaction conditions (standard or metal-assisted) and, interestingly, on the nature of the nucleophile used.
- Calvani, Federico,Crotti, Paolo,Gardelli, Cristina,Pineschi, Mauro
-
p. 12999 - 13022
(2007/10/02)
-
- Studies Related to Thromboxane A2: A Formal Synthesis of Optically Active 9α,11α-Thiathromboxane A2 Methyl Ester from Levoglucosan
-
A synthesis of (+/-)-7-exo-(n-butyloxy)-2-oxa-6-thiabicycloheptane (4) from 2-(benzyloxy)-5,6-dihydropyran (5) (Scheme I) and the conversion of levoglucosan 20 into 36 (Scheme IV) are described.Compound 36 is an intermediate in a published synthesis (Scheme III) of the biologically active 9α,11α-thiathromboxane A2 methyl ester (19).
- Kale, Vilas N.,Clive, Derrick L. J.
-
p. 1554 - 1563
(2007/10/02)
-
- Classical Synthesis of a New Class of Compounds via Coupling of Sugars and Amino Acids
-
A new class of pharmacologically interesting compounds has been synthesized through a novel SN2 displacement of the CF3SO2 group in benzyl 2,3-anhydro-4-trifluoromethylsulphonyl-α-D-ribopyranoside (1) and its β-L-isomer (2), by a variety of suitably protected naturally occurring amino acids: the reaction pathway also provides an efficient route to benzyl 2,3-anhydro-β-L- and -α-D-lyxopyranosides .
- Malik, Abdul,Kowollik, Wolfgang,Scheer, Peter,Afza, Nighat,Voelter, Wolfgang
-
p. 1229 - 1231
(2007/10/02)
-