· Put your student numbers on the upper right-hand corner of each page. Number every page. Do not put your name on the material you turn in. I would rather grade your work without knowing who you are.

· Type your Assignment on a computer; draw your molecular structures with a computer drawing program. If you need help or if you need programs to do this, see me.

· List and draw exact structures and reactions of the closest precedent to your proposed synthetic operations for every step you reference. I will take off points for steps for which there is no literature reference. Do not cite text books! Do not cite Wikipedia or other web resident knowledge. You may use this information, but you will have to look up the original literature.

· Photocopy important pages (not the whole paper) from journals and attach them to your homework. Make sure that the reference is written on the page. If need be, write it at the top of the photocopy. Put a page number on the photocopied page. Refer to the photocopied page in your text. Don't make it difficult for the grader to conclude that someone can do the synthesis. Use a highlighter or circle the pertinent sections of the work you photocopy. Do not use a red pen.

{10 pts.} Devise diastereospecific routes to the target molecule above using two different retrosyntheses. Different syntheses can be devised by breaking different bonds at the first or second disconnection. One of these must apply a Sonogishira coupling.

{10 pts.} Choose the best synthesis out of the two based on synthetic concepts discussed previously. Explain why one synthesis is better than the other. Detail the best forward synthesis proposing reagents and conditions with references. The format for this problem can be found on the web at: