W_07_215_E1_key - Name:_KEY_ Page 1(W.07.215.E1p1) I. (20...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Name:______KEY_______________ Page 1(W.07.215.E1p1) Cl O Cl TESADH Molecue A a) ( JOC , 2007 , 72 , 30) Using the reagents W110A and TESADH, a single stereoisomer of Molecule A undergoes a completely stereoselective addition of a hydride (without a protonation) to yield alkoxide intermediate B which then forms Oxirane C. Oxirane C b) ( JOC , 2007 , 72 , 139) The reaction shown below froms a new C-C bond. The proposed mechanism for this reaction includes two steps: an electrophilic addition (A E ) followed by an elimination. Draw the two step mechanism. O S S HOBF 3 O S S H 2 OBF 3 + + W110A Show appropriate stereochemistry at both relevant centers of the alkoxide intermediate B. 8 3 I . ( 20 points) The electrophile O S S HOBF 3 + O S S H 2 OBF 3 + O S S H HOBF 3 2 points intermedaiate 3 points each set of arrows O S S H can show mechanism through assisted ionization using the S stabilized carbocation O H CH 3 H Cl Cl O - Cl O - H CH 3 H Cl Cl OR Instead of a single stereoiosmer of Molecule A, mixture of the enantiomers of Molecule A was treated with NaBH 4 . Four different oxiranes resulted from this reaction: Oxirane C and its enantiomer, and Oxirane D and its enantiomer. Draw the oxiranes in the boxes below.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/21/2008 for the course CHEM 215 taught by Professor Koreeda during the Spring '07 term at University of Michigan.

Page1 / 5

W_07_215_E1_key - Name:_KEY_ Page 1(W.07.215.E1p1) I. (20...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online