“Whoa! It’s like Spotify but for academic articles.”

Instant Access to Thousands of Journals for just $40/month

Try 2 weeks free now

Effects of ring contraction on the conformational preferences of α‐substituted proline analogs

The structural consequences derived from the incorporation of either a methyl or a phenyl group at the α carbon of proline were recently investigated by quantum mechanical calculations (J Org Chem 2008, 73, 3418). In this work, the effect produced by contraction of the pyrrolidine ring on such α‐substituted proline analogs has been explored using the same computational methods. Specifically, the intrinsic conformational preferences of the N‐acetyl‐N′‐methylamide derivatives of the lower proline homolog L‐azetidine‐2‐carboxylic acid (Aze), characterized by a four‐ instead of a five‐membered ring, and its α‐methyl (αMeAze) and α‐phenyl (αPhAze) derivatives have been determined using quantum mechanical calculations and compared to those observed before for the proline counterparts. Replacement of the pyrrolidine ring by an azetidine cycle leads to a reduction of the conformational flexibility, especially for the Aze and αMeAze derivatives, which should be attributed to the quasi‐planar geometry of the four‐membered ring. Furthermore, the azetidine nitrogen shows pyramidalization, which depending on the peptide backbone conformation favors the formation of an attractive N–H···N interaction or alleviates a severe steric hindrance. Calculations on different environments predict that the tendency of αMeAze to adopt γ‐turns is higher than that of unsubstituted Aze and α‐methylproline, this feature being in full agreement with the experimental observations available. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 98–110, 2012. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Biopolymers Wiley

Loading next page...

You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy unlimited access and
personalized recommendations from
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $40/month

Try 2 weeks free now

Explore the DeepDyve Library

How DeepDyve Works

Spend time researching, not time worrying you’re buying articles that might not be useful.

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from Springer, Elsevier, Nature, IEEE, Wiley-Blackwell and more.

All the latest content is available, no embargo periods.

See the journals in your area

Simple and Affordable Pricing

14-day free trial. Cancel anytime, with a 30-day money-back guarantee.

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Best Deal — 25% off

Annual Plan

  • All the features of the Professional Plan, but for 25% off!
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

billed annually