in high yields and released from their corresponding acetals with 2014,,, 17-471. Protecting Groups Hydroxyl Protecting Groups 26 Protection of 1,2 & 1,3-diols 4. p-Methoxybenzylidene acetals: Cleavage: Hydrolyzed about 10 times faster than regular benzylidenes OO R1R2 HOOH R1R2 Acid CH(OMe)2 CHO or OMe OMe OMe Can be oxidatively removed with CAN 19.47b and c). Any type of content formally published in an academic journal, usually following a peer-review process. 1,2- and 1,3-diols have been developed. DOI: 10.1002/9781118905074.ch02. Some of the most common: OOOO 'acetonide' most stable least stable Usually, 1,2 >1,3>1,4 HO OH OH O OH O O O 5: 1 On: … Benzylidene-Type Photolabile Diol Protecting Groups, Structurally Simple Benzylidene-Type Photolabile Diol However, the conversion of hemiacetals into acetals is catalyzed only by acids (Eqs. high chemical efficiency. Protecting Groups in Organic Synthesis-8 Ready acetal protection of diols Cyclic acetal are wonderful protecting groups for 1,2 and 1,3 diols. I am guessing it should be possible to protect 1,3-diols with acetone too - after all, a methyl group is hardly the worst axial substituent to have. Protecting Groups: A Necessary Evil 3 Note, however, that each protecting group incorporated in a multi-step synthesis increases the synthesis by two non-productive steps reducing the overall yield and efficiency of the synthesis. Structure-Guided Design of Fluorescent S-Adenosylmethionine Analogs for a High-Throughput Screen to Target SAM-I Riboswitch RNAs. Protection for the Hydroxyl Group, Including 1,2- and 1,3-Diols. However, I am not sure how much this principle extends to protection of compounds with only two hydroxyl groups. 19.10 ACETALS AND THEIR USE AS PROTECTING GROUPS 923 The formation of hemiacetals is catalyzed not only by acids but by bases as well (Problem 19.16b, p. 910). Protecting Groups, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified. Chemistry & Biology 2014, 21, 345-356 protecting groups for releasing Two structurally simple photolabile Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. Two structurally simple photolabile protecting groups for releasing 1,2- and 1,3-diols have been developed. The diols can be protected in high yields and released from their corresponding acetals with high chemical efficiency. Scott F. Hickey, Ming C. Hammond. The diols can be protected