Hard labour

Later on, all the protecting groups will be removed the silyl groups with fluoride and the p-methoxybenzyl ether by oxidation with Ce(IV). In Ley s recently completed synthesis9 of azadirachtin 64 after 22 years of hard labour the key intermediate was 65. You will notice benzyl ethers, acetals and a silyl ether. This is a more modem, one might almost say minimalist, use of protection. In an ideal world no protecting groups would be necessary but in a real synthesis they will almost certainly be required as we shall see in the rest of the book. But our aim should be to keep them to a minimum. 

The invention of novel column hardware and complex stationary phases would be fruitless without the hard labours of dedicated chromatographers in the development of their art. The likes of Gregor Mann 1 8 Henri Colin 19 Geoff Cox 1-9 110] and Roger Nicoud[111] have been relentless in the arena of process modelling and optimization for preparative separations, to name a but few. 

Fielding, M. (2001). Taking education really seriously Four years hard labour. In M. Fielding (Ed.)... 

In Taking education really seriously Four years hard labour. London RoutledgePalmer Smyth, J., Dow, A., Hattam, R., Reid, A., Shaddock, G. (2000). Teachers work in a globalising economy. London Palmer Press... 

The Seatown Council Group was only in the most rudimentary sense a group at all. In April 1966 twelve senior Aldermen and Councillors tabled a motion urging the Council to press the government to create an enforced work scheme for convicted Mods and Rockers. The motion received wide publicity, under such headings as Make the Rockers Dig and Hard Labour Plan For The Rowdy Mods . The exact text was as follows ... 

The motive for developing commercial NMR sensors of horticultural products hardly needs to be laboured. Consumers expect their fruit and vegetables to be of consistent high quality, at optimum ripeness, juiciness and texture and, of course, free from bruises, disease, infestation and other internal quality defects. Unfortunately for the fruit or vegetable grower, many of these quality factors are outside their control. Factors such as the weather, harvesting conditions and natural biological diversity mean that the quality of... 

Easy is the descent of Avernus Night and day the portals of gloomy Dis stand open but to reverse your step and to win again the daylight—that s labour, that s hard work, Virgil, Aeneid, vi, 126. 

You may feel that we have laboured hard to justify an example of regioselectivity which any experienced organic chemists would have predicted would go this way round. They would have drawn curly arrows 6.151 creating the canonical structures 6.152 to express an electron distribution making C-4 of the diene nucleophilic and C-3 of the acrolein electrophilic. They would acknowledge... 

Juice travels a long distance low yields high labour requirements hardly used at all nowadays... 

---