Ch_322b_12.08

Ch_322b_12.08 - (an unstable salt) fast C=O R R' ketone +...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Alcohol Products from Grignard Additions By proper choice of the Grignard and carbonyl compounds, a great variety of primary, secondary, and tertiary alcohols may be synthesized. Primary Alcohols from Formaldehyde R-MgX δ + δ− + C=O H H formaldehyde R- C-O MgX H H H 3 O + R- CH 2 OH primary alcohol Secondary Alcohols from Aldehydes R-MgX δ + δ− + C=O R' H aldehyde R- C-O MgX R' H H 3 O + R- CHOH secondary alcohol R' Tertiary Alcohols from Ketones R-MgX δ + δ− + C=O R' R'' ketone R- C-O MgX R' R'' H 3 O + R- COH tertiary alcohol R' R''
Background image of page 1

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

View Full DocumentRight Arrow Icon
Some Examples MgBr phenylmagnesium bromide + H 2 C=O formaldehyde diethyl ether CH 2 OMgBr H 3 O + CH 2 OH benzyl alcohol CH 3 CH 2 MgBr ethylmagnesium bromide + C 6 H 5 C=O H benzaldehyde diethyl ether CH 3 CH 2 CHOMgBr H 3 O + CH 3 CH 2 CHOH 1-phenyl-1-propanol CH 3 MgI methylmagnesium iodide + =O cyclohexanone diethyl ether CH 3 OMgI H 3 O + CH 3 OH 1-methylcyclohexanol
Background image of page 2
Tertiary Alcohols from Esters Two equivalents of the Grignard reagent add to esters in sequential steps leading to tertiary alcohols. R-MgX δ + δ− + C=O R' R''O ester R-C-O-MgX R' R''O initial addition product
Background image of page 3

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

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: (an unstable salt) fast C=O R R' ketone + R''OMgX byproduct RMgX addition of second equivalent to ketone R-C-O-MgX R' R salt H 3 O + R-C-O-H R' R tertiary alcohol Overall R'COR'' O = ester (i) 2 equiv RMgX/ether solvent (ii) H 3 O + (workup) R-C-O-H R' R tertiary alcohol + R''OH alcohol byproduct Example CH 3 MgI methylmagnesium iodide + O = COCH 2 CH 3 ethyl benzoate diethyl ether COCH 2 CH 3 CH 3 OMgI unstable-(CH 3 CH 2 OMgI) O CCH 3 CH 3 MgI CCH 3 CH 3 OMgI H 3 O + CCH 3 CH 3 OH 2-phenyl-2-propanol Quiz 12.08 Provide the organic products of the following Grignard reactions. CH 3 CH 2 MgBr + CH 2-CH 2 O diethyl ether H 3 O + C 6 H 5 MgBr + CH 3 CH O = diethyl ether H 3 O + CH 3 MgI + CH 3 COCH 3 O diethyl ether H 3 O + excess CH 3 CH 2 CH 2 CH 2 OH C 6 H 5 CHCH 3 OH CH 3 CCH 3 OH CH 3 + CH 3 OH...
View Full Document

Page1 / 5

Ch_322b_12.08 - (an unstable salt) fast C=O R R' ketone +...

This preview shows document pages 1 - 5. Sign up to view the full document.

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